She’ll be bringing her expertise to the Milk Street Cooking School on May 18 (use code GOGRILL to get 20% off when you sign up), but in the meantime, she was nice enough to hop on a call and discuss the importance of good charcoal, why grill marks are overrated, and the difference between competition barbecue and feeding her family.
How did you get into grilling?
This is a funny question because everybody always wants to know this. So, my background—I'm a biologist—and I used to work in wildlife television and documentaries as a producer, doing all the David Attenborough shows, that kind of thing. And then I had my son—he’s now nearly twenty! When I had him, I had to give telly up because I couldn't travel so much anymore, but I realized quite quickly that I wasn't cut out for full-time mothering. I was a better mummy when I worked as well. And food was the thing that I felt like I was naturally quite good at. I've always cooked. It was my passion, even as quite a small child. I grew up in a single-parent family and me and my brother were both expected to put dinner on the table in the evening. We had to cook because Mum was working full-time, so we learned to cook from a very young age and it turned out that I was pretty good at it. My brother's a really good cook as well.
“I guess it started out as a sort of act of selfishness.”
But I think the way that I've looped back to specializing in fire and outside cooking is because I want to be outside. I want to be outside in the fresh air, in nature. I don't want to be locked in a kitchen. I guess it started out as a sort of act of selfishness. When my kids were toddlers, it was like, this is actually quite boring. So when they were small I would take them outside and I'd light a fire and they'd help cook their own dinner over the fire and it just kind of grew. I just became obsessed with it. It was a way of combining my love of cooking with my love of wanting to be outside.
The obsession seems to have paid off!
I'm naturally quite geeky. I really like science and I think if I can explain the why in a recipe as well as what, it helps people learn and it makes them kind of click, “Oh, that's why they always say to do it like that.”
Flipping it the other way: There are a lot of myths that are perpetuated in recipe writing that don't necessarily stand up from a scientific point of view. If you've got a sort of scientific, geeky mind, it's quite good to question why, and then when you look into it, actually, there isn't really a good reason, so let's try and do it this way. It works better, you know?
When people think of grilling, they have two main options: gas or charcoal. Out of those two, which is your favorite and why?
Definitely charcoal because I like the solid fuel nature of it. You take some charcoal or some wood and you light a fire and you create the fire rather than just turning the button and clicking it on. I think gas is fine, and I'm not snobby about other people cooking with gas. It works really well and not everybody is as obsessed about the fire as I am.
Tell me a little bit about open-fire cooking, because that's related to charcoal but not quite the same.
The reason we generally use charcoal over a pure wood product is because good, pure charcoal is 95% pure carbon, and it's a very pure, clean substance and heat source for cooking. And it's hotter—charcoal actually burns two to three times hotter than wood. It's this pure, more consistent product for cooking on, whereas wood, because it's much more natural—you know, you cut the tree down, you dry the tree, you light the tree—there's much more variability with wood cooking. Some woods are more smoky, some woods are less smoky, some are more sort of smelly. There's different properties and variables, so with open-fire wood cooking, you would generally use wood in an open environment, maybe a little bit of charcoal for extra heat, but it's a more characterful way of cooking. You can get variability and you can get different sorts of aromas, different smokes, and that kind of thing.
If you've got good, pure charcoal, it shouldn't smoke at all and it shouldn't taste of anything. It's a very pure carbon product so if you want to add smoke, because you want to smoke your food, you need to add an element of wood into that cooking equation. I've done a lot of work with the big barbecues in Texas; traditionally they would always cook over wood, sort of long and slow, to get that smoke in.
One myth you talk about in your book "Seared" is the idea that all charcoal has to ash over before you use it. Is that true?
Everybody thinks that you have to do that with charcoal, wait for it to be white and ashy, but if you've got very good, pure charcoal you don't have to do that. In fact it would be a waste to do that, because you've just been wasting all that heat energy when you could be cooking on it.
So the white and ashy thing is more because a lot of charcoal has chemical additives in it, and you have to burn those chemicals off before it's passable and/or safe to cook your food on it, because you don't want your food to taste of petrol chemicals. So the white and ashy thing is like a one-sentence way to say you've got to get your coals ready for cooking. You don't want your sausages to taste of petrol, you know?
“For me the charcoal is an ingredient, as much as the meat or the fish.”
I'm such a big advocate for shouting about the value of good charcoal because it's a really important part of the story for me. There's a lot of really shit charcoal in this world that's made very badly out of really dubious sort of forestry sources, and lots of chemicals, and there's a lot of nasty stuff out there. If we can buy very pure lumpwood charcoal that has been sustainably made, it's just a really important part of the equation for me with cooking.
I run a cookery school here in Bristol, and I always say that I'd rather people cooked on gas than use shit charcoal. Gas is honestly quite a pure product; it doesn't add any taste to the food and neither does good charcoal. But bad charcoal—you're never going to get a great result. For me the charcoal is an ingredient, as much as the meat or the fish.
So the charcoal to buy is lump charcoal?
I always buy pure lumpwood. I'm quite specific about charcoal. I don't know a great deal about charcoal sourcing in America but in the UK there's a real growing movement of artisan charcoal makers that make it in a very pure, old-fashioned way. In the same way that a lot of people now think more about the sourcing of their meat, and buying organic meat or free-range meat rather than factory-farmed meat. It's a similar sort of vibe really. You've got really rubbish charcoal which is like the equivalent of factory-farmed chicken, versus good charcoal which is like the equivalent of spending more to get a much better product to give you a better cooking result. And if you teach people how to use charcoal they end up using a lot less charcoal. Most people use way too much charcoal, you don’t actually need very much to cook something. It's just teaching people how to control the fire management and the rate that it burns.
That leads into my next question: I just have a Weber Kettle grill...
It's my favorite barbecue, my Weber Kettle. It's like my number one barbecue.
Yeah, I love it! But obviously there aren’t any temperature control dials. How do you control the heat?
Really good question. And it's so simple to answer: It's about the flow of oxygen. [For] the combustion equation you need the fire triangle—you need fuel, which is charcoal; you need an ignition spark, so a match; and you need oxygen. If you have more oxygen, you have hotter, quicker fire, and if you have less oxygen, you have a slower, more gentle fire. This is why barbecues have air vents. You open the vent if you want it hotter and you shut the vent if you want it cooler.
And the second critical thing is you never want to put the charcoal everywhere. Fully combusting charcoal can burn to something like 500 Celsius, so if you have charcoal all over the bottom of your Kettle, that's all you'd have. It'd be like having max nine on your dial on your gas grill, kind of like you're wok-cooking everything. If I put a strip of charcoal here, that would be 500 Celsius, but over here [on the other side], you would find it's probably about 100 Celsius, and in the middle it would probably be about 200 Celsius, so what you get is a temperature gradient on a horizontal plane. Basically, you have an area of charcoal and you move the food between very hot, very cool, and in the middle, like you would turn the dial up and down on your gas cooker.
It’s very elegant! Another thing that's so neat about the two-zone setup that you just described is you have a stove and an oven in one.
Exactly! If you put the lid on, you create an oven. And people are kind of amazed that you can bake a cake in a barbecue, which is something that I do all the time. You can make an oven, all you need to do is have a hot fire, so lots of heat, but the food is not near the heat, and you're just cooking purely with convection currents which are like a hairdryer. Convection currents are remarkably efficient. It's how we cook in a fan oven in the kitchen, like a roast chicken for example—you can roast that so it's beautifully crispy. It never sees any flame.
Another thing you touch on in “Seared” is that you really need to get an external thermometer, because there are problems with the one that comes on top of the grill.
The one on the top of the grill is only measuring the hot air at the precise point where the probe is. So if you've got three kinds of heat going on—you've got infrared heat, which is the lit charcoal, that's called the mother heat, the source heat. And then that quickly goes into anything conductible like the metal grill surfaces, and then you've got conduction heat. The third type of heat is hot air like we talked about—the convection currents. The lid thermometer is only measuring the convection currents, the hot air underneath where the little probe is. It's just a partial picture. It's partly useful, because it gives you a gauge, but it's not the whole picture.
“If you're looking, you're not cooking, and it's done when it's bloody well done.”
If you're cooking meat or fish, an actual food probe, like a Thermapen—that's a thing that's going to tell you if your food is cooked or not. And you can get thermometers that sit on the grill surface that would give you an idea of what temperature the grill surface was. I don't have one of those. I think one of the reasons I like fire is it's really instinctive. Every fire is a tiny bit different to the one you lit before, so you're constantly sort of shifting and you're having to bend and flex and adapt a little bit, and I like that with cooking. It can be hard to write about grilling because there are so many variables, so it's more that you have to give people the knowledge to understand what to do with those variables, give them the skills to problem solve.
That’s why I quite like all that detail in my book. It’s really difficult to write a fire-cooked recipe that has got absolute guarantees, you know? It's not like “Bang it in the oven at 300 Fahrenheit and it'll be perfect in twenty minutes.”
It is more instinctual and you have to use your senses.
If you're looking you're not cooking.
Exactly! If you're looking, you're not cooking, and it's done when it's bloody well done.
Let’s talk about some myths: Why don't you bring your meat to room temperature before barbecuing?
And I've got dogs, I don't particularly want a steak sitting on the worktop for five hours. And if you have something like a whole chicken—a whole chicken is going to be way longer than that. It's not a truth, it's a thing that we've been told we should do. I'd like to encourage everybody to have a go—stick a probe in it and see what happens.
Let’s talk about brines and marinades: What's the most effective way to get flavor into meat?
Flavor doesn't really permeate meat. [Laughs] That's the simple answer. If I took a piece of chicken and I covered it in a spice rub, whatever you fancy—smoked paprika, oregano, chili—and we left that chicken in the fridge for a week, the marinade, the flavor molecules, will only ever go like two or three millimeters into the surface of the chicken. If we left it for six weeks, it would be the same. It can't go any deeper because the molecules of all of those flavors are too big. They just can't travel through.
“Flavor doesn't really permeate meat. That's the simple answer.”
So stuff like rubs and the flavorings in marinades, you can very much consider them as a surface treatment. If you’ve got more surface, you get more flavor. I think rubs and marinades work on things with a bigger surface area, so kebabs, skewers, small bits of meat that have got a big surface area. You're going to get more bang for your buck basically.
If you have a 2-kilo joint of pork, the rub would only be on the outside, it would never get into the middle, so if you want that maximum flavor from a spice rub, you're better to either accept that it's only going to be on the surface layer, then make sure all your guests get a bit of the outside and a bit of the inside, or you do something where there's a lot of smaller bits, or if you took a chicken breast or chicken thighs and you cut slashes into it, you're increasing the surface area so the rubs go deeper into the meat.
But salt is a little different
Salt is a little different because salt is a teeny tiny little molecule and it has the ability to penetrate all the way through. It takes time to do that which is why dry brining is a really good thing. Salt is a natural flavor enhancer—that’s why we like it, it makes the thing taste of more of the thing. The steak tastes more steak-y. It’s the reason we like a tiny bit of salt in baking recipes, it just ramps up the flavor.
But the salt has a more important kind of chemical thing going on, in that it breaks the bonds between the protein fibers, which means that the meat can't contract up when it hits the heat. I always like to show people a bundle of spaghetti—each strand of spaghetti is like a protein [fiber], and those are in a tightly bound bundle, but the salt breaks those [bonds], so the bundle is loose. When the bundle hits the heat, the meat can't contract up. And that's good because the name of the game with all meat cooking is to keep the meat juicy.
“The easiest and best thing you can do to a meat is just sprinkle it with salt...”
All meat is sort of 70-75% water, like us, so you want to keep as much of that 70% in your steak as possible. By chemically breaking these bonds, the meat is not going to squeeze out all of its water as soon as it hits the heat. It just keeps everything much juicier and you've ramped up the flavor potential. The easiest and best thing you can do to meat is just sprinkle it with salt, leave it for a couple of hours in the fridge, 24 hours if you can. It's an easy win.
Do you use liquid brines at all?
Occasionally I will, but mostly I don't because you need to use a lot more salt, so it's kind of cheaper to start with dry brining. I'm a really big fan of encouraging people to buy the best meat that they can, that's been slow-grown. With wet brining, the salt pulls in extra water so it gets juicier, but I would argue that the water could have a diluting effect to the actual flavor of the meat itself. You've got this beautiful slow-grown beef—I don't want to add extra water to it, I just want to taste it as a pure product rather than as a slightly diluted product.
What do you think about grill marks?
Oh my god! So! The grill bar marks are where the Maillard reaction has happened, and that is a chemical chain reaction which increases the number of flavor molecules. And we know, if I presented you with a piece of steak that I had boiled, it would be kind of grey. If I presented you with a piece of steak that had been beautifully seared, it would be brown. If I gave you both of those, you know which one you'd pick, yeah? It's the same with a loaf of bread. You know that wonderful brown crust you get on a loaf? That's the same reaction, the Maillard reaction, the browning reaction. So I always say that having stripes, the Maillard reaction has happened—beautiful—but it hasn't happened here [between the grill marks], so you're missing out on a load of potential. If the whole thing was brown, then it's like bang, your steak's going to taste amazing, instead of half amazing.
How much fat do you trim off a big piece of meat?
It kind of depends. If you’re cooking a whole brisket and if you're smoking, you want the smoke to get to the meat rather than just the fat. So the pit masters in Texas, they trim their brisket pretty hard. I don't trim as hard as they would because I'm not cooking for a competition, and I like the taste of that really good beef fat; it's a beautiful thing when it's cooked properly. I trim a little bit but I don't over-trim. I guess the golden rule for me is the more fatty your meat, the more indirect you should be cooking it. If you had a really super fatty cut of steak, if you whack it directly in the heat, you're going to get a lot of flare ups, so cooking it a little bit indirectly is often the better thing.
“Fish don't have saturated fats, because if they had a load of solid fats at room temperature, they couldn't swim.”
Being good at fire cooking—it all goes back to the control you have over the heat source, and the more in control you are, the better the results. Take it steady. Most things cooked a little bit off of the heat, for a little bit longer, the end result is going to be juicy. Steak's a bit of a different one because you really want to develop that browned crust, but the more fatty your meat, the more you should be cooking it indirectly.
That’s a really interesting thing that I came to learn about the differences between meat and fish. In meat, the fat is saturated fat—it's like butter. So it's solid at room-temperature. Fish don't have saturated fats, because if they had a load of solid fats at room temperature, they couldn't swim.
They couldn’t move!
They'd be rigid in the water. So fish have unsaturated fats like olive oil, so they can swim!
I can't believe I've never made that connection before.
Until you think about it, you don't know it. It's just I've spent so much time thinking about the differences here. Fish are not particularly fatty creatures for start, but the fat that they do have is unsaturated like olive oil; they need practically no heat for that fat to start running really fluid, you know? So it's very delicate, and the protein is very delicate because the fat is unsaturated and fluid, so it doesn't need a lot of heat to get it cooked.
So meat is like spaghetti, long thin strands. Fish protein is arranged more like a brick wall, so it’s lots of little short blocks stacked on top of each other, which we see as flakes of fish whens it’s cooked. So the actual structure of fish protein is very delicate. And the fat is very delicate and fluid. That's why fish falls apart and sticks to your grill. It's just a different thing, it's a whole different kettle of fish. So you need to learn how to cook it. Generally for fish it's very, very hot and very, very quick.
Pivoting back to beasts for a moment: What’s your favorite steak to grill?
My second favorite is ribeye. Ribeye is a lot more fatty, so you would be more likely to get those flare ups that I talked about with the fat catching fire, and I think because it has that lovely solid nugget of fat in the middle, it's a steak that is better cooked a little bit beyond rare, because you want render that fat, to make that fat beautiful and palatable. It needs to be soft and melting. So I would cook a ribeye kind of medium-rare or even medium, whereas a hanger steak, I'd eat it rare, like super rare.
Can you briefly describe what the stall is and how you get around it?
And there's two ways: You can set it out. If you just kept running forever, you would at some point get hotter and hotter and hotter. With meat, if you just kept it cooking, eventually it would pass through the stall and it would start cooking again. The rate that that happens is very variable, so it might take an hour, it might take two hours, it might take six hours, because each bit of meat is very different—animals, they're all different, they're not the same. It's like humans, we all come in different shapes and sizes, same with animals.
“People get this macho thing, like, ‘Oh, I didn't wrap it. I ran out the stall.' So what?”
What you can do to drive your meat over the stall is to wrap it. You wrap it in butcher's paper, or you wrap it in foil, you can wrap it in both things, and that's the same as if you were running and sweating but you had a jacket on. You wouldn't cool down, you'd just get hotter and hotter and hotter. You'd stop the cooling effect. That's why you wrap.
People get this macho thing, like, “Oh, I didn't wrap it. I ran out the stall.” So what? Bully for you! Great. It’s the difference between eating your dinner at 6 o’ clock and eating at 10 o’ clock—you’ve got no idea when it's going to be ready. So really from a purely practical point of view, because I want to feed my family or feed my friends, I generally would always wrap it.
Do you take it off once it starts climbing again?
Yeah. Or you just take it through to the temperature. The argument against wrapping is that sometimes you don't get the bark—the crust on the outside—and it's just a bit of a balance. If you wrap in foil, because foil is super non-permeable, the bark will be softer. If you wrap in butcher's paper, because it can breathe a little bit more, the bark is generally better. So wrapping in foil is quicker, wrapping in paper is always a bit slower, so I generally wrap in paper. For me it's like a middle ground.
Im not making competition barbecue. I just want to feed people. That's what I like doing. Maybe that's what women bring to the party. I think generally we're very practical. It's about feeding our family. It doesn't have to be competition-worthy. I can make amazing food. It's just cooking.
This interview has been lightly edited for clarity.
Photography by Jason Ingram.
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